Abstract Background Immune checkpoint inhibitor therapy has revolutionized oncologic treatment. The treatment primarily targets T-cells but also modulate B-cells. As a result, immune related adverse events such as immune checkpoint inhibitor colitis (ICI-C) are common and can be potentially life-threatening. Treatment of ICI-C often involves infliximab (IFX) in case of steroid refractoriness or dependency. IFX can lead to acute severe infusion reactions often caused by anti-drug antibody formation. We aimed to investigate the incidence and characteristics of infusion reactions in ICI-C as well as subsequent management of ICI-C following these reactions. Methods This was a retrospective cohort study including all patients with ICI-C treated with IFX from 2020 through 2024. Patients were followed for one year from initiation of IFX. Reactions were defined as acute systemic reactions during infusion with IFX resulting in permanent discontinuation. The reactions were scored using the Universal Standardized Drug Allergy Reaction (USDAR) grading scale. Secondary, subsequent management of ICI-C following reactions was described. A cohort of 176 bio-naïve and thiopurine-unexposed patients initiating IFX for IBD was used as a control group. Results Ninety-nine patients with ICI-C were treated with IFX during the study period, 93% of whom received concomitant corticosteroids (CS). Twenty-five percent received a single IFX infusion, 50% received two, 15% received three and 9% received four or more. Diarrhea resolved within 14 days following the first infusion in 63% of patients. Overall, 4 (4.0%) patients experienced acute infusion reactions. This incidence was comparable to the IBD control group where 8 (4.5%) of 176 patients had an acute severe infusion reaction (p = 1.0). The reactions occurred at the 2nd (n = 2, 50%) or 3rd infusion (n = 2, 50%). Three patients had a USDAR grade of one, while one patient had a grade of two. All cases were managed with iv anti-histamine and CS and none resulted in hospital admission. Three patients were subsequently treated with golimumab (n=2 attained remission), and one went successfully into remission with vedolizumab. Other drug related adverse events to IFX such as dermatitis, drug induced liver injury or infections, were not significantly different in the two groups (ICI-C: 8/99 (8.1%) vs IBD: 18/176 (10.2%), p = 0.67). Conclusion Despite substantial risk factors comprising episodic therapy and highly activated state of immune response, the risk of acute severe infusion reactions to IFX does not appear to be increased in patients with ICI-C compared to IBD. Switching to another TNF-inhibitor can be successful following a reaction. Conflict of interest: Ms. Ovesen, Pernille Dige: None Dahl, Emilie: Has received material support for a clinical trial from Takeda, has stock options in Novo Nordisk and Zealand Pharma. Zhao, Mirabella: Other: Travel fees from Takeda Pharma A/S Poulsen, Anja: Research grants and personal fees from Janssen, Janssen Research & Development, Takeda, Tillotts Pharma, AbbVie, and MSD consultancy fees and advisory board honoraria from Agomab, Eli Lilly, Bristol Myers Squibb, Johnson & Johnson, and Takeda and has served as national coordinator for clinical studies sponsored by Agomab, Boehringer Ingelheim, and Bristol Myers Squibb. Burisch, Johan: Grant: Johnson & Johnson, MSD, Takeda, Tillots Pharma, BMS, Novo Nordisk Personal Fees: Celgene, MSD, Pfizer, AbbVie, Takeda, Tillots Pharma, Samsung Bioepis, BMS, Pharmacosmos, Galapagos, Zealand Pharma, Orion Pharma, Ferring, Johnson & Johnson Steenholdt, Casper: Lectures for Takeda, MSD and Janssen-Cilag research grant from Takeda. Seidelin, Jakob Benedict: Research grants from Takeda and Johnson and Johnson, and national coordinator of studies from AbbVie, Arena Pharmaceuticals, Ely Lilly, and Boehringer Ingelheim.
Ovesen et al. (Thu,) studied this question.